Circuit controlling system



Patented Dec. 19, 1939 PATENT OFFICE 2,183,775 CIRCUIT CONTROLLING SYSTEM Theodore F. Pike,

St. Paul, Minn., assignor to Automatic Control Company, St. Paul, Minn., a corporation of Minnesota Application July 5, 1988, Serial No. 217,578

8 Claims.

This invention relates to circuit controlling systems designed to the purpose of controlling pumps for pumping into elevated tanks for storing liquids to be drawn oil from the tanks at intervals as desired for use, and which pumps are adapted to be started and stopped in response to alterations in pressure produced by changes in the level of liquid in said elevated tanks.

The production of a circuit controlling system for the purpose as herein presented and devised to satisfactorily accomplish all of the services or functions it desirably. should accomplish, required consideration of various diiferent propositions. For reasons of economy, in a liquid system of type intended to be controlled according to the invention, the pipe connection for conveying theliquid from the operating pump of said liquid system to the elevated tank, or tanks, thereof also constitutes a part of the supply line of the liquid 90 system leading from said tank, or tanks, to the intended locations of use of the liquid, so, obviously, there is occasion for momentary surges of liquid in such a liquid system, and it is desirable and practically necessary to accomplish control of the pump of a liquidsystem as set forth independently of the effect of momentary surges in the liquid system. In the instance of many liquid systems of the character here intended to be controlled, deep well turbine pumps are employed, and each of these deep well turbine pumps customarily revolves backward at high speed upon cessation of operation of the pump due to recession of liquid through said pump into the well. This backward revolution of the pump is of course but momentary, continuing only until the. liquid free to fall by gravity into the well has traveled downwardly past the operating mechanism of the pump. It is essential, in order that the deep well pump be not impaired, that said deep well pump be incapable of again operating after'cessation of operation of the pump until free liquid has traveled by gravity downwardly past and below the pump operating mechanism. Otherwise, liquid i'orced upwardly by the pump will come into contact under great force with downwardly flowing liquid and create injurious action and/or reaction upon the pump operating mechanism. Assuming the pump of a liquid system of character to be controlled according to the invention to be standing still or idle, sooner or later, in some instance or other, there inevitably will be, unless provision is made to the contrary, momentary drop in pressure in the liquid system (due to the opening of large pump of a liquid system of character drawolls at the locations of use) of suflicient magnitude to cause said pump to be started up when in fact the level of liquid in the elevated tank, or tanks, of said liquid system is above the level at which said pump is intended to be brought into operation. .It is essential, in order that the 5 adapted .to be controlled according to the invention be not started at times other than when this is intentional, that control of said pump be accomplished independently of momentary drops in 10 pressure in said liquid system of magniture sumcient to reduce the pressure in the liquid system toor below that at which the pump is set and intended to operate in response to the falling of the level of liquid in the elevated tank, or tanks, 16 of said liquid system to a predetermined low level. Cessation of operation 01' a pump of a liquid system of character intended to be controlled according to the principles of the present invention should be positive. Otherwise, the 20 pump on occasion may not stop operating when this is the intentiomand overflow of the elevated tank, or tanks, will be the result. Stated differently, it is desirable that the pump of a liquid system as set forth be so controlled that it will 25 becaused to cease to operate without fail either when the level of liquid in the elevated tank, or tanks, 01' the liquid system reaches the high predetermined level, or when, for any reason there is failure of the current or other part of the circuit controlling system. And, too, cessation of operation 01' the pump of a liquid system of the character as recited should be accomplished in response to the attainment oi predetermined high liquid level in its elevated tank, or tanks, 86 ranging within comparatively narrow limits, especially when the predetermined controlling high liquid level is relatively near to, or as close as possible to, the top of said elevated tank, or tanks. Otherwise, the tank, or tanks, could on occasion 40 possibly be caused to overflow. So, predetermined high liquid level in the tank, or tanks, of the liquid system should not only constitute the phenomenon of the circuit controlling system by reference to which the cessation oi operation 45 of the pump 01' said liquid system should be accomplished without fail in any instance, but, additionally, the high level of liquid in said tank,

or tanks, which is adapted or .devised to cause operation of mechanism for bringing said pump 50 to rest should desirably be allowed to vary from time to time, during practical operation of the circuit controlling system, between only the narrowest of limits. And, it is needless to say, a circuit controlling system for the purpose as set as forth should incorporate features and characteristics of construction designed to the purpose of reducing to a minimum the liability of failure of the current, or of any part, of the circuit controlling system.

An object of the present invention is to provide a circuit cont-rolling system designed to control pumps, particularly deep well pumps, for pumping into elevated storage tanks for liquids to be drawn off for occasional use and which circuit controlling system will satisfactorily accomplish all of the services or functions it should ideally accomplish, especially those services or functions of the circuit controlling system which have relation to the solution of the several different problems or propositions hereinbefore enumerated.

More explicitly, the invention has for its purpose to provide a circuit controlling system for accomplishing control of the pump, or deep well pump, of a liquid system in connection with which the circuit controlling system is adapted to be employed, and which circuit controlling system will accomplish control of said pump independently of the effect of momentary surges in the liquid system; will so accomplish control of a deep well pump employed as an entity of the liquid system that said deep well pump will be incapable of again starting up operation on any occasion after ceasingto operate until free liquid has been allowed an ample interval of time to travel by gravity downwardly past and below the pump operating mechanism or equipment; will so accomplish control of said pump that it will when idle or at rest be started up only on each occasion when the level of liquid in the tank, or tanks, of the liquid system reaches predetermined low level at which the pump is set or intended to operate and remains at, or below, said predetermined low level for an interval of time, and will not be started up when idle or at rest due to momentary drops in pressure in said liquid system to pressures as low as or below the pressure at which the pump is caused to operate in response to the falling of the level of liquid in said tank, or tanks, to said predetermined low level; will so accomplish control of said pump that it will be caused to cease to operate without fail either when the level of liquid in the tank, or tanks, of the liquid system reaches predetermined high level at which the pump is set or intended to be brought to rest, or when there is failure of the current or other element or part of the circuit controlling system; will so accomplish control of said pump that cessation of its operation will result in response to the attainment of predetermined high liquid level in the tank, or tanks, of the liquid system ranging between the very narrowest of limits amounting in practice to 'substantially a constant predetermined controlling high liquid level for causing said pump to cease its operation; and will incorporate features and characteristics of construction designed with the end in view of reducing to a minimum the liability of failure of the current, or any other element or part, of the circuit controlling system.

With the above objectsin view, as well as others which will appear as the specification proceeds, the invention comprises the construction, arrangement and combination of parts as now to be fully described and as hereinafter to be specifically claimed, it being understood that the disclosure herein is merely illustrative and intended in no way in a limiting sense, changes in details of construction and arrangement of parts being permissible so long as within the spirit of the invention and the scope'of the claims which follow.

In the accompanying drawings forming a part of this specification,

Fig. 1 is a front elevational view, parts being broken away, of an apparatus made according to the invention;

Fig. 2 is an enlarged fragmentary transverse sectional view of the apparatus of Fig. 1, taken on line 2-4 insaid Fig. 1;

Fig. 3 is a further enlarged fragmentary vertical longitudinal sectional view, taken as on line 33 in Fig. 2;

Fig. 4 is a diagrammatic view of the electrical system of the apparatus of Figs. 1, 2 and 3;

Fig. 5 is a diagrammatic view of an electrical system of slightly modified form for the apparatus; and

Fig. 6 is a diagrammatic view of the apparatus of Figs. 1 to 3 included in a circuit controlling system.

With respect to the drawings and the numerals of reference thereon, I0 denotes a casing of the apparatus, shown in Fig. 1 in its proper, upright position. Said casing I0 is adapted to be supported, in any ordinary or preferred manner (not shown), upon a wall or other vertical member. The casing III as disclosed is of rectilinear conformation.

Said casing I0 houses three electrical switches, represented II, I2 and I3, respectively, and additionally houses other elements of the apparatus. Each of the ,switches I I, I2 and I3 is in the illustration of the invention disclosed a mercury switch of ordinary or preferred construction.

The switch I I may for convenience be designated the low level switch of the circuit controlling system, and, broadly stated, is operative to open and closed conditions in response to fluctuations in pressure in a pressure system. More explicitly, said switch II normally is adapted to be in closed condition only when the level of liquid in the tank, or tanks, of a liquid system to be controlled according to the invention is at predetermined low level intended as the phenomenon by reference to which a motor (not shown), for actuating a pump (also not shown) for forcing liquid into said tank, or tanks, is to be energized or set into operation. At all other times the switch II normally is adapted to be in open condition.

The switch I2 may for convenience be designated the start switch of the circuit controlling system, and is operative to open and closed conditions through the instrumentality of a relay, designated generally at I4. The relay I4 is as disclosed a heat relay the thermostatic element or bimetallic blade I5 of which is designed to be actuated, to thus cause said switch I2 to be closed and opened, in response to energization and deenergization of a lamp or other resistance or heat producing element or member I6. Said element or member I6 is included in an energizing circuit therefor which also includes the switch I I. When said switch II is in closed condition the element or member I5 is energized and when the switch II is in open condition said element or member I6 is deenergized. The switch I2 is operative to closed condition in response to energization of said relay I4. In turn, said switch I2 when closed is adapted to cause a circuit to be completed through the motor for actuating the pump for forcing liquid into the tank, or tanks, of the liquid system to be controlled. Stated differently, movement of the switch II, the low level switch,

to closed condition will not, in practical use 01' the circuit controlling system, in any instance contrary, said motor cannot be put into operation heat producing element or member I6,

ating'motor, when idle or at rest, started up immediately when the switch I I moves to closed condition in response to falling of the liquid level in the tank, or tanks, to predetermined low level intended to cause said motor to be set into operation, but said motor, instead, will commence to operate at an interval of time thereand only when the'heat producing member I6 has had opportunity by reason of its energization by closing the switch I I to heat up the thermostatic element I5 and thus actuate the switch I2 to closed condition. Conversely, the pump actuating motor once energized by closing of the switch I2, in response to heating up of said thermostatic element I5, cannot become de-energized merely by opening the switch II. Said motor, instead, will in each instancecease to operate at a later period, when and only when the thermostatic element has had suificient time to cool down after de-energization of the element or member I6 to an extent which will cause the switch I2 to be moved to the open condition of the circuit for the pump actuating motor circuit.

The switch I3 may for convenience be designated the high level switch of the circuit controlling system, and is also operative to open and closed conditions in response to fluctuations in pressure in a pressure system. More explicitly, the switch I3 normally is adapted to be in open condition only when the level of liquid in the tank. or tanks, of the liquid system being controlled is at predetermined high level intended as the phenomenon by reference to which the pump actuating motor of said liquid system is 'to be deenergized or caused to be idle. At all other times the switch I3 normally is adapted to be in closed condition. The ceasing of operation of the pump actuating motorof, a liquid system being controlled according to the principles of the invention is controlled by the switch I3, the high level switch, of the apparatus, said switch being included in a circuit for controlling the motor cirhowever, that the switch I3 cannot after having moved to open condition in response to predetermined high level of liquid in the tank, or' tanks, of the liquid system and caused the pump actuating motor of said system to be de-energized be again closed and alone cause said motor to be energized. On the contrary, after the switch I3 has been moved to open condition in response to the attainment of predetermined high liquid level in the tank, or tanks, and the circuit for the pump actuating motor has been broken, said circuit cannot be closed again save by closing of the switch II in response to the attainment of predetermined low liquid level in said tank, or tanks, and later closing as well of the switch I2 in response to energization of the heat producing element or member I3 caused by closing of said switch II.

A conduit adapted to be connected with a liquid system to be controlled and to impart the pressure at any time prevailing in said liquid system to the apparatus is denoted I1. Said conduit II includes a branch or passageway I8 thereof connected with and leadinginto a diaphragm housing I9 and a'branch or passageway 20 thereof connected with and leading into a diaghragm housing 2|. I9 and 2I are open at their upper portions and are secured, as at 22, in openings in -a lower wall of the casing III. c

A diaphragm or metallic bellows 23 in the housing I9 constitutes an element of the apparatus for causing the switch II to be opened and closed in response to fluctuations in pressure in the conduit I1. Said diaphragm or metallic bellows 23 is closed save at its upper portion 24 which is suitably fitted and secured in the upper portion of the housing I9. Together, the diaphrag'm or metallic bellows 23 and the diaphragm housing I9 provide a fluid-tight chamber or concavity 25 below and around said diaphragm or bellows 23 and with which the branch'or passageway IIl communicates.

What may be termed a low level setting of the apparatus is designated shown,

against longitudinal movement in an upper wall of the casing I0. A nut 28 threaded upon said screw bolt 21 is fixed against turning movement and guided for vertical movement or adjustment by means of a guide element or finger 29 rigid with said nut and slidable in a vertical guideway 30 upon a side wall of the casing III. A coil spring 3| has its upper end made rigid with said nut 28. and the lower end of said coil spring 3| is con veniently secured, as at 32, to an end portion 33 of a substantially horizontal lever 34. The coil spring 3| acts to draw or force the end portion 33 of the level 34 upwardly, and a stop member 35 upon the casing I 0 limits upward movement of said mentioned end portion 33.

The lever 34 extends inwardly of the casing away from the coil spring 3I and the stop member 35 and includes an end portion 36 thereof disposed in alinement with or metallic bellows 23.

of said lever 34, between its end portion 33 and its end portion 36, is arranged beneath a strap 31 fixed to the lower wall and above the diaphragm AS illustrated, the end portion 33 of the lever 34 has length several times as great as that of the end portion 36 of said lever.

A vertical stud 39 is secured to the base of the diaphragm or metallic bellows 23 and extends upwardly centrally through and above said diaphragm or bellows. Said stud member 39 has an upper pointed end 40 which is pivotaliy engaged against the lower surface of the end portion 36 of the lever 34 at location in spaced relation to the fulcrum 38. Obviously, the coil spring 3| constantly acts upon the end portion 33 of the lever 34, through the instrumentality of the fulcrum 38, to urge the end portion 36 of said lever against the stud member 39. The arrangement is such that the end portion 33 of the lever is brought into engagement with the stop member 35 only when minimum, pressure exists in the The diaphragm housings I An intermediate portion chamber or-concavity 25 and the end portion 36 I is yet in engagement with the stud member 39.

The lever 34 fixedly carries an upstanding hook member 4|. As shown, said hook member 4| is secured upon the upper surface of the end portion 33 of said lever 34 and is situated in comparatively close relation to the fulcrum 38, at the side of said fulcrum opposite the end portion 36. An upper portion of the hook member 4|, spaced from the lever 34, fixedly carries a horizontally disposed pin 42.

A horizontal shaft 43 is'suitably secured to the rear wall of the casing l and extends forwardly from said rear wall. Said shaft 43 is as shown situated at location a trifle beneath the pin 42, within the hook of the hook member 4|, and

' between said pin 42 and the lever 34. A U-shape member rotatably supported upon said horizontal shaft 43 includes a base 44 thereof and spaced apart legs, denoted 45 and 46, respectively, thereof extending upwardly from said base 44. Each leg 45 and 46 is rotatably supported upon the hori zontal shaft 43 at location adjacent the base 44.

The upper portion of the leg 45, above said horizontal shaft 43, is bifurcated and the horizontal pin 42 lies in the slot 41 of the upper bifurcated portion of said leg 45. The upper portion of the leg 46, above said shaft 43, suitably and conveniently carries a clip 48 of ordinary or preferred construction, and said clip 48 in turn suitablyand conveniently supports the electrical or mercury switch H in such manner that said switch is substantially horizontally situated.

The switch II is constructed and arranged to be moved to closed condition by decrease of pressure in the chamber or concavity 25 causing resultant rocking or tilting movement of the lever 34 and its hook member 4| in direction to close said switch and to be moved to open condition by increase of pressure in said chamber or concavity causing resultant rocking or tilting movement of said lever 34 and its book member 4| in direction to opcnsaid switch. The low level setting 26 and associated parts are set up and adjusted so that said switch normally will be in closed condition only when the level of liquid in the tank, or tanks, of the liquid system being controlled is at predetermined low level intended to cause the pump actuating motor of said liquid system to be started up and normally will be in open condition at all other times, as hereinbefore stated.

A diaphragm or metallic bellows 49 in the housing 2| constitutes an element of the apparatus for causing the switch Hi to be opened and closed in response to fluctuations in pressure in the conduit |1. Said diaphragm or metallic bellows 49 is closed save at its upper portion 50 which is suitably fitted and secured in the upper portion of the housing 2|. Together, the diaphragm or metallic bellows 49 and the diaphragm hous ng 2| provide a fluid-tight chamber or concavity below and around said diaphragm or bellows 49 and with which the branch or passageway 29 communicates.

What may be termed a high level setting of the apparatus is designated generally at 52. As shown, said high level setting 52 includes a verticalscrew bolt 53 mounted for rotation but fixed aganst longitudinal movement in an upper wall of the casing ID. A nut 54 threaded upon said screw bolt 53 is fixed against turning movement and guided for vertical adjustment by means of a guide element or finger 55 rigid with said nut and slidable in a vertical guideway 56 upon a side wall of the casing In. A coil spring 51 has its upper end made rigid with said nut 54, and the lower end of said coil spring 51 is convenient ly secured, as at 58, to an end portion 59 of a substantially horizontal lever 60. The coil spring 51 acts to draw or force the end portion 59 of the lever upwardly, and a stop member 6| upon the casing in limits upward movement of said mentioned end portion 59.

The lever 60 extends inwardly of the casing away from the coil spring 51 and the stop member 6| and includes an end portion 62 thereof disposed in alinement with and above the diaphragm or metallic bellows 49. An intermediate portion of said lever 60, between its end portion 59 and its end portion 62, is arranged beneath a strap 63 fixed to the lower wall of the casing l9, and the upper portion or base 64 of said strap provides a fulcrum for said lever 60 above the lever. As illustrated, the end portion 59 of the lever 60 has length several times as great as that of the end portion 62 of said lever.

A vertical stud member 65 is secured to the base of the diaphragm or metallic bellows 49 and extends upwardly centrally through and above said diaphragm or bellows. Said stud member 65 has an upper pointed end 66 which is pivotally engaged against the lower surface of the end portion 62 of the lever 60 at location in spaced relation to the fulcrum 64. Obviously, the coil spring 51 constantly acts upon the end portion 59 of the lever 68, through the instrumentality of the fulcrum 64, to urge the end portion 62 of said lever against the stud member 65. The arrangement is such that said end portion 59 of the lever is brought into engagement with the stop member 6| only when minimum pressure exists in the chamber or concavity 5| and the end portion 62 is yet in engagement with the stud member 65.

The lever 60 fixedly carries an upstanding hook member 61. As shown, said hook member 61 is secured upon the upper surface of the end portion 59 of said lever 68 and is situated in comparatively close relation to the fulcrum 64, at the side of said fulcrum opposite the end portion 62. An upper portion of the hook member 61, spaced from the lever 68, fixedly carries a horizontally disposed pin 68.

A horizontal shaft 69 is suitably secured to the rear wall of thecasing l0 and extends forwardly from said rear wall. Said shaft 69 is as shown situated at location a trifle beneath the pin 68, within the hook of the hook member 61, and between said pin 68 and the lever 60. shape member rotatably supported upon the horizontal shaft 69 includes a base 19 thereof and spaced apart legs, denoted 1| and 12, respectively, thereof extending upwardly from said base 10. Each leg 1|, 12 is rotatably supported upon the horizontal shaft 69 at location adjacent the base 10. The upper portion of the leg 1|, above said horizontal shaft 69, is bifurcated and the horizontal pin 68 lies in the slot 13 of the upper bifurcated portion of said leg 1|. The upper portion of the leg 12, above said shaft 69, suitably and conveniently carries a clip 14 of 0rdnary or preferred construction, and said clip 14 in turn suitably and conveniently supports the electrical or mercury switch H! in such manner that said switch is substantially horizontally situated.

The switch |3 is constructed and arranged to be moved, to open condition by increase of pressure in the chamber or concavity 5| causing resultant rocking or tilting movement of the lever and its hook member in direction to open said switch and to be moved to closed condition by decrease of pressure in said chamber or concavity causing resultant rocking or tilting movement of said lever 60 and its hook member 61 in direction to close said switch. The high level setting 52 and associated parts are set up and adjusted so that said switch I3 normally will be in open condition only when the level of liquid in the tank, or tanks, of the liquid system being controlled is at predetermined high level intended to cause the pump actuating motor of said liquid system to be brought to rest and normally will be in closed condition at all other times, as

hereinbefore stated.

The lamp or heat producing element or member I6 of the heat relay I4 is suitably and insulatively supported upon the rear wall of the casing I0, and the thermostatic element or bimetallic blade I5 of said heat relay is in relatively close, surrounding relation to said lamp, element or member I8. Said element or blade I5 has one end thereof fixedly supported, as at 15, upon the rear wall of said casing I0 and the free end I6 of the element or blade I5 suitably supports a clip 11. In turn, the clip I1 conveniently carries the electrical or mercury switch I2 in such manner that said switch is substantially horizontally situated.

Said switch I2 is constructed and arranged to be moved to closed condition in response to energization of the heat relay I4 causing resultant rocking or tilting movement of the element or blade I5 in direction to close said switch and to be moved to open condition in response to de-energization of said heat relay causing resultant rocking or tilting movement of said element or blade I5 in direction to open said switch.

Incoming lead wires 99, I00 and IN are separately attached to terminals I02, I03 and I04, respectively. A magnetic relay switch includes movableswitch arms I05, I06 and I01 which are also separately attached to the terminals I02, I03 and I04, respectively. The movable switch arms I05, I06 and I0! are insulatively interconnected by an element I08 secured to an armature I09 surrounded by an operating coil IIO. A conducting piece III upon the armature I09 is adapted to bridge spaced apart, fixed contact members H2 and H3. The movable switch arms I05, I 06 and I01 are, respectively, adapted to separately engage fixed conducting members H4, H5 and, H6, and lead wires H1, H8 and H9 extend from said fixed conducting members to the pump actuating motor (not shown). A lead wire I8 extends from the fixed contact member I2 to a binding post8I and a lead wire 19 extends from the fixed contact member II3 to a binding post82. A lead wire I 20 extends from the incoming lead wire IOI to said fixed contact member II2, a lead wire l2I extends from the incoming lead wire I00 to the operating coil III], and a lead wire 80 extends from said operating coil to a terminal 83. A lead wire 84 extends from the terminal 8| to the switch I2 and a lead wire 85 extends from the terminal 82 to the switch I3. A lead wire 86 extends from said switch I2 to the terminal 83 and a lead wire 81 extends from said switch I3 to said terminal 83. A lead wire 88 extends from the incoming lead wire I08 to a terminal 89 and a lead wire 90 extends from the incoming lead wire 89 to a terminal 9i. A lead wire 92 extends from the terminal 89 to the switch II and a lead wire 93 extends from said switch II to a terminal 94.

a lead wire 91 extends from said resistance to the lamp or heat producing element I8, and a lead wire 98 extends from said lamp or element I6 to the terminal 94.

Upon the closing of the switch II a circuit is completed through the lamp or element I8 to cause said lamp or element to be energized, said circuit being traced from the incoming lead wire 99 through the lead wire 90 to the terminal 9|, thence through the lead wire 95, the resistance 96 and the lead wire 91 to the lamp or element I8, and thence back to the incoming lead wire I00 through the lead wire 98, the terminal 94, the lead wire 93, said switch II, the lead wire 92, the terminal 89 and the lead wire 88. In

due time after closing of the switch I I the switch I2 -is closed in response to energization of the lamp or element I8. Upon the closing of said switch I2 the pump actuating motor for the liquid system being controlled is set in operation, and the pumping of liquid into thetank, or tanks, of said liquid system raises the level of liquid in said tank, or tanks, so that the pressure in the chamber or concavity 25 is raised and the switch II is moved to open condition to thus cause the switch I2 to be later opened.

The magnetic relay is arranged in the circuit controlling system to be energized to close its several switches when the start switch I2 is closed and to be de-energized to open its several switches when said start switch is open. That is, the operating coil IIO of the magnetic relay is arranged in a circuit as follows-from the incoming lead wire IOI through the lead wire I20 to the fixed contact member I I2, thence through the lead wire 18 to the terminal 8|, thence through the lead wire 84 to the start switch I2, and thence back to the incoming lead wire I00 through the lead wire 86, the terminal B3, the lead wire 80, said operating coil H0 and the lead wire I2I. Closing of the switch III, H2, H3 completes a holding circuit for the operating coil traced as follows-from the incoming lead wire IOI through the lead wire I20 to the fixed contact member II2, thence through the conducting piece III, the fixed contact member H3 and the lead wire I9 to the terminal 82, thence through the lead wire 85, the switch I3 and the lead wire 81 to the terminal 83, and thence back to the lead wire I00 through the lead wire 80, said operating coil H0 and the lead wire I2I.

Closing of the switches I05II4, I06--II5 and/5 I0II l6 causes the pump actuating motor to be energized. 1

In Fig. 5 there is disclosed an electrical system of slightly modified form. The disclosures of Figs. 4 and 5 are alike, except that where the lead wire 85 in Fig. 4 extends between the start switch I2 and the terminal 83, the lead wire 88' in Fig. 5 extends between the start switch and the terminal 82. The part of the circuit in Fig. 4 traced from the terminal 8I through the lead wire 84, the start switch I2 and the lead wire 86 to the terminal 83 is in Fig. 5 traced from said terminal 8| through said lead wire 84, said start switch I2, the lead wire 86', the terminal 82, the lead wire 85, the stop switch I3 and the lead wire. 81 to said terminal 83. For all practical purposes in the operation of the circuit controlling system the circuits of Figs. 4 and 5 are substantially the same. In Fig. 5, however, surging in the liquid system after start of operation of the pump and while the switch I2 is closed will if of sufficient magnitude to create pressure equivalent to that existing at predetermined high liquid level cause temporary breaking of the circuit for the magnetic relay. This mentioned circuit will of course immediately close, and there is small likelihood of such high pressure existing in a liquid system when comparatively low water. level prevails.

The operating parts of the circuit controlling system are disclosed in the drawings as when predetermined low liquid level in the tank, or tanks, of a liquid system being controlled has just been reached, the thermostatic element or bimetallic blade I5 not having had time to heat up and thus be flexed or warped to cause the start switch I2 to be moved to closed condition. Said start switch is at this time open, the low level switch II has just closed, and thestop switch I3 is closed. Said operating parts being so positioned, the circuit for the lamp or element I6 is closed, said circuit being traced from the incoming lead wire 99 through the lead wire to the terminal 9I, thence through the lead wire 95, the resistance 96, the lead wire 91, said lamp or element I6, the lead wire 98, the terminal 94 and the lead wire 93 to the low level switch II, and thence through the lead wire 92, the terminal 89 and thelead wire 88 back to the incoming lead wire I00. The pump actuating motor circuit will not become closed until the start switch I2 is closed in response to heating up of the element or blade I5, and once closed, by energization of the operating coil II 0, cannot possibly open, even though the holding circuit should fail, until an interval of time has elapsed sufllcient to permit said element or blade I5 to cool oif and thus actuate the switch I2 to cause the main circuit through said operating coil to be broken.

The holding circuit once made can be broken only by opening of the stop switch t3. -Imrnediately upon opening said stop switch, in response to predetermined high liquid level in the tank, or tanks, the operating coil III] is deenergized and the switches of the magnetic relay open to break the holding circuit. Thereafter, the circuits including the operating coil can be made again only by closing of the low level switch II and subsequent closing of the start switch I2 in the manner as before set forth.

The novel and improved circuit controlling system evidently accomplishes control of the pump of a liquid system independently of the effect of surges in said liquid system. The heating up of the element or blade I5 required to cause the switch I2 to be closed before the pump actuating motor circuit will be closed to start the pump when idle introduces the condition that said pump actuating motor circuit cannot be broken subsequent to the start of operation of the pump at least until an interval of time elapses after said pump is set to work. That is, the heated up element or blade I5 causes the start switch I2 to take independent control of the pump actuating motor circuit. Surges in the liquid system obviously cannot affect said switch I2.

A deep well pump employed as an entity of a liquid system being controlled will be incapable of again starting up operation on any occasion after ceasing to operate, due to the arrangement as illustrated and described including the heat relay I4. Upon the closing of the circuit including the start switch I2 the pump actuating motor circuit is closed, as is also the circuit including the stop switch I3 and the switch of the magnetic relay. Practically immediately after the pump starts up operation, the low level switch II is opened. In a comparatively short time after the heat relay is de-energized the switch I2 moves to open condition. If the pump stops after said start switch is opened it cannot start up again, assuming the magnetic relay circuit to be broken, until the element or blade I5 is again heated up in the manner as explained. In practice, the interval required to heat up the element or blade I5 and close the switch I2 will be great enough to permit free liquid to travel by gravity down past the pump operating mechanism into the well before the pump when at rest can start up operation.

Should there be momentary, drops in pressure in the liquid system, as by the drawing ofl of large quantities of liquid, to pressures as low as or below the pressure at which the pump is caused to operate in response to the falling of the level of liquid in the tank, or tanks, of said system while the pump is idle and when the level of liquid in said tank, or tanks, is above predetermined low level at which the pump is set or intended to operate, the pump will not be started up in any instance when the low pressure condition mentioned does not prevail for a sufficient interval of time which will cause the switch I2 to become closed. Should such low pressure condition prevail for the period required to cause the start switch I2 to be moved to closed condition, no harm will be done. The pump simply will be brought into operation and will cease operating when predetermined high liquid level is attained.

The pump will obviously cease to operate upon failure of current or other essential element or part of the circuit controlling system, for the reason that continuous operation of said pump is dependent upon the continuance of current in the magnetic relay circuit including the stop switch I3. Operation of the pump evidently will be discontinued immediately upon opening of said stop switch I3 and thus operation of said pump in each instance will cease upon the attainment of predetermined high liquid level in the tank, or tanks, amounting in practice to substantially a constant predetermined controlling high liquid level.

Attention is particularly called to the fact that the circuit controlling system can incorporate a really durable heat producing device, such, for example, as the lamp IS, the reason for this being that the interval of time which may be consumed to heat the element or blade I5 need not be unduly limited. The amount of heat required in the present embodiment is quite small and the heat may be made to operate upon the whole of the element or blade I5 during an interval of comparatively great length. The interval the lamp or element I6 may impart its heat to the element or blade I5 satisfactorily may be much longer than the interval which would be permissible were the heat relay I4, for instance, associated with a switch for the purpose of causing operation of the pump to cease. In any instance of the stopping of operation of the pump through the instrumentality of a heat relay, the resistance or heat producing element of the relay is required to work accurately within quite narrow limits so pumping will be discontinued in each instance at a reasonably controlled predetermined high liquid level in the tank, 'or tanks. In the present disclosure, the heat relay need not be at all sensitive. The heat applied to the thermostatic element need not move it appreciably farther after causing it to flex slightly beyond the position causing the start switch to be closed. In the case of a heat relay adapted to be actuated after high liquid level isreached to cause the pump to cease operating, it is in practice necessary to employ a heat producing element which is both delicate and sensitive and yet required to quickly produce a comparatively large amount of heat. Such a heat producing element is liable to quickly burn out. And, too, a circuit controlling system dependent upon a heat relay to cause the pump of a liquid system being controlled to be brought to rest by energization of said heat relay will not cause cessation of operation of said pump upon failure of said heat relay. Such fact constitutes a serious objection to the use of a surge snubber in the stop circuit of a circuit controlling system of the general nature as herein presented because overflows are both undesirable and dangerous and are particularly dangerous during freezing Weather.

It is to be understood that while the invention has been illustrated and described as more especially useful for controlling the pump of a liquid pressure system, features and characteristics of the invention are applicable as well to the accomplishment of control of a pump for a gas pressure system adapted to be started and stopped in response to fluctuations or alterations in the pressures of said gas pressure system.

What is claimed is:

l. A motor circuit controlling system operative in response to alterations in pressure of a pressure system, comprising a first switch adapted to be closed by decrease of pressure and to be opened by increase of pressure in said pressure system, a second switch, a circuit controlled by said first switch including means for controlling said second switch, a third switch adapted to be closed by decrease of pressure and to be opened by increase of pressure in said pressure system, an operating relay for said motor circuit, a main circuit for said relay controlled by Said second switch, and a holding circuit for said relay controlled by said third switch.

2. A motor circuit controlling system operative in response to alterations in pressure of a pressure system, comprising a first switch adapted to be closed by decrease of pressure and to be opened by increase of pressure in said pressure system, a second switch, a circuit controlled by said first switch including means for causing said second switch to be closed an interval of time after said first switch is closed and to be opened an interval of time after the first switch is opened, a third switch adapted to be closed by decrease of pressure and to be opened by increase of pressure in said pressure system, an operating relay for said motor circuit, a main circuit for said relay controlled by said second switch, and a holding circuit for said-relay controlled by said third switch.

3. A motor circuit controlling system operative in response to alterations in pressure of a pres sure system, comprising a first switch adapted to be closed by decrease of pressure to a predetermined low pressure and to be opened by increase of pressure above said predetermined low pressure in said pressure system, a second switch, a circuit controlled by said first switch including of time has elapsed after 7 means for causing said second switch to be closed an interval of time after said first switch is closed and to be opened an interval of time after the first switch is opened, a third switch adapted to be closed by decrease of pressure below a predetermined high pressure and to be opened by increase of pressure to said predetermined high pressure in said pressure system, an operating relay for said motor circuit, a main circuit for said relay controlled by said second switch, and a holding circuit for said relay controlled by said third switch. 1

4. A motor circuit controlling system operative in response to alterations in pressure of a pressure system, comprising a first switch adapted to be closed by decrease of pressure to a predetermined low pressure and to be'opened by increase of pressure above said predetermined low pressure in said pressure system, a second, delay action' switch, a circuit controlled by said first switch including means for causing said second, delay action switch to be closed only when an interval of time has elapsed after said first switch is closed and to beopened only when an interval the first switch is opened, a third switch adapted to be closed by decrease of pressure below a predetermined high pressure and to be opened by increase of pressure to said predetermined high pressure in said pressure system, an operating relay for said motor circuit, a main circuit for said relay controlled by said second switch adapted to be closed when the second switch is closed and to be open when the second switch is open, and a holding circuit for said relay controlled by said third switch adapted to be closed in response to closing of said main circuit while the third switch is closed.

5. A motor circuit controlling system operative in response to alterations in pressure of a pressure system, comprising a first switch adapted to be closed by decrease of pressure and to be opened by increase of pressure in said pressure system, a second switch, a circuit controlled by said first switch including a heat relay for controlling said second switch, a third switch adapted to be closed by decrease of pressure and to be opened by increase of pressure in said pressure system, an operating relay for said motor circuit, a main circuit for said relay controlled by said second switch, and a holding circuit for said relay controlled by said third switch.

6. A motor circuit controlling system operative in response to alterations in pressure of a pressure system, comprising a first switch adapted to be closed by decrease of pressure to a predetermined low pressure and to be opened by increase of pressure above said predetermined low pressure in said pressure system, a second switch, a circuit controlled by said first switch including a heat relay for causing saidsecond switch to be closed an interval of time after the first switch is closed and to be opened an interval of time after said first switch is opened, a third switch adapted to be closed by decrease of pressure below a predetermined high pressure and to be opened by increase of pressure to said predetermined high pressure in said pressure system, an operating relay for said motor circuit, a main circuit for said relay controlled by said second switch, and a holding circuit for said relay controlled by said third switch. 1

7. A motor circuit controlling system operative in response to alterations in pressure of a pressure system, comprising a first switch adapted to be closed by decrease of pressure to a predetermined low pressure and to be opened by increase of pressure above said predetermined low pressure in said pressure system, a second, delay action switch, a circuit controlled by said first switch including a heat relay for causing said second switch to be closed only when an interval of time has elapsed after said first switch is closed and to be opened only when an interval of time has elapsed after the first switch is opened, a third switch adapted to be closed by decrease of pressure below a predetermined high pressure and to be opened by increase of pressure to said predetermined high pressure in said 4 pressure system, an operating relay for said motor circuit, a main circuit for said relay controlled by said second switch adapted to be closed when the second switch is closed and to be open when the second switch is open, and a holding circuit for said relay controlled by said third switch adapted to be closed in response to closing of said main circuit while said third switch is closed.

8. A motor circuit controlling system operative in response to alterations in pressure of a pressure system, comprising a first switch adapted to be closed by decrease of pressure to a predetermined low pressure and to be opened by increase of pressure above said predetermined low pressure in said pressure system, a second switch, a circuit controlled by said first switch, a resistance element in said circuit, a thermostatic element for controlling said second switch adapted to be actuated by absorption of heat due to energization of said resistance element by closing .of said first switch to cause the second switch to be moved to closed position and to remain closed so long as said first switch remains closed, said thermostatic element being adapted to be actuated by loss of heat due to de-energization of said resistance element upon opening of said first switch to cause the second switch to be moved to open position and to remain open so long as said first switch remains open, a third switch adapted to be closed by decrease of pressure below a predetermined high pressure and to be opened by increase of pressure to said predetermined high pressure in said pressure system, an operating relay for said motor-circuit, a main circuit for said relay controlled by said second switch adapted to be closed when the second switch is closed and to be open when the second switch is open, and a holding circuit for said relay controlled by said third switch adapted to be closed in response to closing of said main circuit while the third switch is closed.

THEODORE F. PIKE. 

